HI I am still new here so bear with me if I don't post something right...
But I have never read that verse and gotten the meaning that the person who wrote the letter did. Let me explain..
1 Thes 4: 13
But I would not have you to be ignorant, brethren, concerning them which are
asleep, that ye sorrow not, even as others which have no hope.
Thats what he quoted but here is that verse as it is written in my Emphatic Diaglott which is a Greek interlinear that emphasizes certain words in sentences so as to give a better understanding of how that Greek sentence was written ( the all caps words are all caps in the book)
And we do not wish you to be ignorant, Brethren, concerning THOSE HAVING FALLEN ASLEEP, so that you may not grieve as THOSE OTHERS who HAVE not a Hope.
So it's my understanding is that the "THOSE OTHERS" In that verse are the other people who grieve over dead people. They have no hope of seeing them again or don't really believe that they will.
Thats my understanding..don't grieve over people who have died (or fallen asleep) like other people who don't have an understanding that they are just asleep. This really fits in with the whole eternal torment hell thing because even people today who are christians may not really believe they will see there loved ones again especially if they weren't in there church, or baptized etc etc..
I don't know just what I think I would love some feedback on this

Also I feel a little funny because I have only posted a few times and each time it seems like I am talking about the Emphatic Diaglott.. I really am more than some guy who is in love with that book lol it just seemed to happen like that